package com.java.common.utils.ip;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.math.NumberUtils;

import com.java.common.utils.StringUtils;
import com.java.common.utils.html.EscapeUtil;

/**
 * 获取IP方法
 *
 * @author Administrator
 */
public class IpUtils {

    private static final String UNKNOWN = "unknown";

    private static final String LOCAL_IP = "127.0.0.1";

    public static String getIpAddr(HttpServletRequest request) {
        if (request == null) {
            return UNKNOWN;
        }
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Forwarded-For");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        String colon = ":";
        if (ip.contains(colon)) {
            return LOCAL_IP;
        }
        ip = EscapeUtil.clean(ip);
        String comma = ",";
        if (ip.contains(comma)) {
            return ip.split(comma)[0];
        }
        return ip;
    }

    public static boolean internalIp(String ip) {
        byte[] addr = textToNumericFormatV4(ip);
        return internalIp(addr) || LOCAL_IP.equals(ip);
    }

    private static boolean internalIp(byte[] addr) {
        if (StringUtils.isNull(addr) || addr.length < NumberUtils.INTEGER_TWO) {
            return true;
        }
        final byte b0 = addr[0];
        final byte b1 = addr[1];
        // 10.x.x.x/8
        final byte sectionOne = 0x0A;
        // 172.16.x.x/12
        final byte sectionTwo = (byte) 0xAC;
        final byte sectionThree = (byte) 0x10;
        final byte sectionFour = (byte) 0x1F;
        // 192.168.x.x/16
        final byte sectionFive = (byte) 0xC0;
        final byte sectionSix = (byte) 0xA8;
        switch (b0) {
        case sectionOne:
            return true;
        case sectionTwo:
            if (b1 >= sectionThree && b1 <= sectionFour) {
                return true;
            }
        case sectionFive:
            switch (b1) {
            case sectionSix:
                return true;
            default:
                return false;
            }
        default:
            return false;
        }
    }

    /**
     * 将IPv4地址转换成字节
     *
     * @param text IPv4地址
     * @return byte 字节
     */
    public static byte[] textToNumericFormatV4(String text) {
        if (text.length() == 0) {
            return null;
        }

        byte[] bytes = new byte[4];
        String[] elements = text.split("\\.", -1);
        try {
            long l;
            int i;
            switch (elements.length) {
            case 1:
                l = Long.parseLong(elements[0]);
                boolean isOut1 = (l < 0L) || (l > 4294967295L);
                if (isOut1) {
                    return null;
                }
                bytes[0] = (byte) (int) (l >> 24 & 0xFF);
                bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
                bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                bytes[3] = (byte) (int) (l & 0xFF);
                break;
            case 2:
                l = Integer.parseInt(elements[0]);
                if (isOutIp(l)) {
                    return null;
                }
                bytes[0] = (byte) (int) (l & 0xFF);
                l = Integer.parseInt(elements[1]);
                boolean isOut2 = (l < 0L) || (l > 16777215L);
                if (isOut2) {
                    return null;
                }
                bytes[1] = (byte) (int) (l >> 16 & 0xFF);
                bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                bytes[3] = (byte) (int) (l & 0xFF);
                break;
            case 3:
                for (i = 0; i < elements.length - 1; ++i) {
                    l = Integer.parseInt(elements[i]);
                    if (isOutIp(l)) {
                        return null;
                    }
                    bytes[i] = (byte) (int) (l & 0xFF);
                }
                l = Integer.parseInt(elements[2]);
                boolean isOut3 = (l < 0L) || (l > 65535L);
                if (isOut3) {
                    return null;
                }
                bytes[2] = (byte) (int) (l >> 8 & 0xFF);
                bytes[3] = (byte) (int) (l & 0xFF);
                break;
            case 4:
                for (i = 0; i < elements.length; ++i) {
                    l = Integer.parseInt(elements[i]);
                    if (isOutIp(l)) {
                        return null;
                    }
                    bytes[i] = (byte) (int) (l & 0xFF);
                }
                break;
            default:
                return null;
            }
        } catch (NumberFormatException e) {
            return null;
        }
        return bytes;
    }

    private static boolean isOutIp(long l) {
        return (l < 0L) || (l > 255L);
    }

    public static String getHostIp() {
        try {
            return InetAddress.getLocalHost().getHostAddress();
        } catch (UnknownHostException e) {
        }
        return LOCAL_IP;
    }

    public static String getHostName() {
        try {
            return InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
        }
        return "未知";
    }

}